diff options
| author | Ralf Baechle | 2011-06-23 12:45:37 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2011-06-27 14:19:20 -0700 |
| commit | 6fab3e1fbc83e6d61e8c28ceab513274183a96f6 (patch) | |
| tree | 626290498b9b0541dc8823b7c2cd0835d2ebbd42 /drivers | |
| parent | 89089158d191ba0195b33ebf35f91ed217d44848 (diff) | |
Staging: Comedi: Build only on arches providing PAGE_KERNEL_NOCACHE
On architectures that don't define PAGE_KERNEL_NOCACHE, the Comedi driver turns
into tragedy:
CC [M] drivers/staging/comedi/drivers.o
drivers/staging/comedi/drivers.c: In function ‘comedi_buf_alloc’:
drivers/staging/comedi/drivers.c:505:41: error: ‘PAGE_KERNEL_NOCACHE’ undeclared (first use in this function)
drivers/staging/comedi/drivers.c:505:41: note: each undeclared identifier is rep orted only once for each function it appears in
make[3]: *** [drivers/staging/comedi/drivers.o] Error 1
Restrict the driver to only those architectures that define PAGE_KERNEL_NOCACHE.
PAGE_KERNEL_NOCACHE is a kludge - some system architectures such as SGI IP27
are even uable to offer uncached operation - at least in the way an unwitting
driver might assume. I haven't looked in details how the driver is using
the area vmaped with PAGE_KERNEL_NOCACHE but maybe doing it XFS-style using
cached memory and the flush_kernel_vmap_range / invalidate_kernel_vmap_range
APIs in conjunction with the DMA API is a practical alternative.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: David Miller <davem@davemloft.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/comedi/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig index 1502d80f6f78..bccdc12e843a 100644 --- a/drivers/staging/comedi/Kconfig +++ b/drivers/staging/comedi/Kconfig @@ -2,6 +2,7 @@ config COMEDI tristate "Data acquisition support (comedi)" default N depends on m + depends on BROKEN || FRV || M32R || MN10300 || SUPERH || TILE || X86 ---help--- Enable support a wide range of data acquisition devices for Linux. |